A favorite theme in children’s and young adult literature is childhood best-friendship so intense that it inspires a ritual or oath to commemorate it. 
This undying sentiment has been distilled into the texting acronym ‘BFF,’ bestowed on that one and only friend who has earned ‘forever’ status. While some girls may attempt to have more than one BFF, technically by calling someone ‘best’ you are designating an exclusivity only one soul mate can earn.
Authors celebrate the bond of best friends, exploring various ways that children and teens pledge their undying devotion. “Blood Sisters” mingle blood, either by pressing bleeding forefingers together or drinking wine with blood dripped into it. 
Oaths to meet again in the distant future have a romantic flair matched only by sworn promises ‘never to forget’ an adventure, as platonic soul mates Tess and Lisa vow in Cinnamon Girls. One of the things I love about their friendship is that it is not encumbered by the murky motivations of seeking validation or sexual pleasure that sullies the girls’ relationships with Andy and Tucker. Friendship asks only that the BFF be trustworthy. Or, if the BFF totally f**ks up, as humans and especially teens are wont to do, the friend must promptly ‘fess up. Almost any failing can be forgiven as long as you are rigorously honest.
Of course modern parents dread that BFF status may be set in stone via a tattoo that their child will have to have painfully lasered off in the future.
No matter how you show the depth of your bond with a female friend, it is my hope that you will remember that feeling forever, keeping the final ‘F” in your BFF pledge for a lifetime. After all, boys come and go but blood sisters are forever.
